1 /*
   2  * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 #include "precompiled.hpp"
  25 #include "gc/z/zAddressSpaceLimit.hpp"
  26 #include "gc/z/zArguments.hpp"
  27 #include "gc/z/zCollectedHeap.hpp"
  28 #include "gc/z/zHeuristics.hpp"
  29 #include "gc/shared/gcArguments.hpp"
  30 #include "runtime/globals.hpp"
  31 #include "runtime/globals_extension.hpp"
  32 
  33 void ZArguments::initialize_alignments() {
  34   SpaceAlignment = ZGranuleSize;
  35   HeapAlignment = SpaceAlignment;
  36 }
  37 
  38 void ZArguments::initialize() {
  39   GCArguments::initialize();
  40 
  41   // Check mark stack size
  42   const size_t mark_stack_space_limit = ZAddressSpaceLimit::mark_stack();
  43   if (ZMarkStackSpaceLimit > mark_stack_space_limit) {
  44     if (!FLAG_IS_DEFAULT(ZMarkStackSpaceLimit)) {
  45       vm_exit_during_initialization("ZMarkStackSpaceLimit too large for limited address space");
  46     }
  47     FLAG_SET_DEFAULT(ZMarkStackSpaceLimit, mark_stack_space_limit);
  48   }
  49 
  50   // Enable NUMA by default
  51   if (FLAG_IS_DEFAULT(UseNUMA)) {
  52     FLAG_SET_DEFAULT(UseNUMA, true);
  53   }
  54 
  55   // Disable biased locking by default
  56   if (FLAG_IS_DEFAULT(UseBiasedLocking)) {
  57     FLAG_SET_DEFAULT(UseBiasedLocking, false);
  58   }
  59 
  60   // Select number of parallel threads
  61   if (FLAG_IS_DEFAULT(ParallelGCThreads)) {
  62     FLAG_SET_DEFAULT(ParallelGCThreads, ZHeuristics::nparallel_workers());
  63   }
  64 
  65   if (ParallelGCThreads == 0) {
  66     vm_exit_during_initialization("The flag -XX:+UseZGC can not be combined with -XX:ParallelGCThreads=0");
  67   }
  68 
  69   // Select number of concurrent threads
  70   if (FLAG_IS_DEFAULT(ConcGCThreads)) {
  71     FLAG_SET_DEFAULT(ConcGCThreads, ZHeuristics::nconcurrent_workers());
  72   }
  73 
  74   if (ConcGCThreads == 0) {
  75     vm_exit_during_initialization("The flag -XX:+UseZGC can not be combined with -XX:ConcGCThreads=0");
  76   }
  77 
  78 #ifdef COMPILER2
  79   // Enable loop strip mining by default
  80   if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) {
  81     FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true);
  82     if (FLAG_IS_DEFAULT(LoopStripMiningIter)) {
  83       FLAG_SET_DEFAULT(LoopStripMiningIter, 1000);
  84     }
  85   }
  86 #endif
  87 
  88   // CompressedOops/UseCompressedClassPointers not supported
  89   FLAG_SET_DEFAULT(UseCompressedOops, false);
  90   FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
  91 
  92   // Verification before startup and after exit not (yet) supported
  93   FLAG_SET_DEFAULT(VerifyDuringStartup, false);
  94   FLAG_SET_DEFAULT(VerifyBeforeExit, false);
  95 
  96   // Verification before heap iteration not (yet) supported, for the
  97   // same reason we need fixup_partial_loads
  98   FLAG_SET_DEFAULT(VerifyBeforeIteration, false);
  99 
 100   if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) {
 101     FLAG_SET_DEFAULT(ZVerifyRoots, true);
 102     FLAG_SET_DEFAULT(ZVerifyObjects, true);
 103   }
 104 
 105   // Verification of stacks not (yet) supported, for the same reason
 106   // we need fixup_partial_loads
 107   DEBUG_ONLY(FLAG_SET_DEFAULT(VerifyStack, false));
 108 
 109   // Initialize platform specific arguments
 110   initialize_platform();
 111 }
 112 
 113 size_t ZArguments::conservative_max_heap_alignment() {
 114   return 0;
 115 }
 116 
 117 CollectedHeap* ZArguments::create_heap() {
 118   return new ZCollectedHeap();
 119 }
 120 
 121 bool ZArguments::is_supported() const {
 122   return is_os_supported();
 123 }